Adjustment Device for Chairs

ABSTRACT

The adjustment device for chairs includes a support assembly, a support arm, a telescopic post and a backrest support. The support assembly has a tube and a fastener penetrating the tube. The tube is provided with a plurality of positioning holes longitudinally arranged in a row. An end of the support arm connects to the tube and is provided with a positioning bolt penetrating one of the positioning holes, and the other end is adapted to connect a cushion. The telescopic post is slidably accommodated in the tube and provided with a plurality of adjusting holes longitudinally arranged in a row for being selectively penetrated by the fastener. The backrest support is connected to the telescopic post for being moved with the telescopic post.

BACKGROUND OF THE INVENTION

1. Technical Field

The invention relates to chairs, particularly to chairs with backrest and cushion height adjustment.

2. Related Art

Chairs are a requirement in everyday life. Besides utility, chairs also must provide enough comfort to different users. A conventional adjustable chair as shown in FIG. 7 utilizes a vee support 80 for adjustably supporting a backrest 81 and cushion 82. The backrest 801 and cushion 82 are slidably mounted on an upper portion 801 and lower portion 802 of the support 80, respectively. This adjustable structure can satisfy different requirements of various users.

However, the support 80 must occupy a specific space because of its vee shape. This may cause inconvenience for small rooms. Furthermore, the support 80 is not retractable, so the top 803 will awkwardly protrude from the backrest 81 when the backrest 81 is adjusted to a lower position. A user sitting on the chair tends to be knocked on his/her head by the protrudent support 80, especially for restless children.

SUMMARY OF THE INVENTION

An object of the invention is to provide an adjustment device for chairs, which can perform height adjustment of backrest without protruding the support from the backrest. This can reduce the occupying space of the chair and is advantageous to storage and transportation. Also, the abovementioned knocking-head problem can be solved.

To accomplish the object, the adjustment device of the invention includes a support assembly, a support arm, a telescopic post and a backrest support. The support assembly has a tube and a fastener penetrating the tube. The tube is provided with a plurality of positioning holes longitudinally arranged in a row. An end of the support arm connects to the tube and is provided with a positioning bolt penetrating one of the positioning holes, and the other end is adapted to connect a cushion. The telescopic post is slidably accommodated in the tube and provided with a plurality of adjusting holes longitudinally arranged in a row for being selectively penetrated by the fastener. The backrest support is connected to the telescopic post for being moved with the telescopic post.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an exploded view of the invention;

FIG. 2 is an assembled view of the invention;

FIG. 3 is a side view showing that both the cushion and backrest are adjusted to low positions;

FIG. 4 is a side view showing that both the cushion and backrest are adjusted to high positions;

FIG. 5 is a back view showing that both the cushion and backrest are adjusted to low positions;

FIG. 6 is a back view showing that both the cushion and backrest are adjusted to high positions; and

FIG. 7 shows a conventional adjustable chair.

DETAILED DESCRIPTION OF THE INVENTION

Please refer to FIGS. 1 and 2. The invention includes a support assembly 1. The support assembly 1 has a tube 11 and a fastener 2 penetrating the tube 11. The tube 11 is provided with a plurality of positioning holes 111 longitudinally arranged in a row. Please further refer to FIG. 5, the fastener 2 has a pin 20 penetrating a hollow portion 110 of the tube 11.

A sleeve 4 is accommodated in the hollow portion 110 of the tube 11. An upper end of the sleeve 4 is formed with a flange 41 by which the sleeve 4 is hung on an upper end of the tube 11. The inside of the sleeve 4 is provided with two longitudinally opposite rails 42 and a though hole 43 penetrating through the sleeve 4 and one of the rails 42. The through hole 43 is corresponding to the fastener 2 in position so that the pin 20 of the fastener 2 is inserted in to the through hole 43. A telescopic post 5 is retractably accommodated in the sleeve 4. The telescopic post 5 is formed with two longitudinal troughs 51 for being engaged by the rails 42. As a result, the telescopic post 5 can be telescoped in the sleeve 4. One of the troughs 51 is provided with a plurality of adjusting holes 52 longitudinally arranged in a row for being selectively penetrated by the pin 20 of the fastener 2. Once one of the adjusting holes 52 is inserted by the fastener 2, the telescopic post 5 is firmly fixed relative to the tube 11.

An end of the telescopic post 5 connects a backrest support 6 for connecting a backrest 200. The backrest support 6 has two opposite ends 60, 61. These two ends 60, 61 are provided with a first connecting portion 600 for fastening to the telescopic post 5 and a second connecting portion 610 for linking the backrest 200, respectively. The first connecting portion 600 is an elastic member made of plastic. The second connecting portion 610 is a pivot for angular adjustment of the backrest 200. Preferably, the backrest support 6 is formed with a curved portion 62 for flexibility.

Please refer to FIG. 6. By means of the curved shape of the backrest support 6, the backrest 200 will be deformed toward the tube 11 when it is pressed. Thus the backrest 200 can flexibly support the user's back. Preferably, the first connecting portion 600 may be further provided with a handle ring 63, which is helpful for moving the chair. A lower end of the telescopic post 5 is provided with a stopper ring 7 encompassing the troughs 51.

The support assembly 1 is connected by a support arm 3. An end of the support arm 3 is formed with a connecting ring 31 slidably around the support assembly 1. The connecting ring 31 is provided with a positioning bolt 32 penetrating one of the positioning holes 111 so that a position of the support arm 3 can be changed. The other end of the support arm 3 is adapted to connect a cushion 100. The cushion 100 is below the backrest 200 in position.

Please refer to FIGS. 3-5. The bottom of the support assembly 1 may be installed with a wheeled seat 300. The handle ring 63 may help to move the wheeled seat 300. The position of the cushion 100 connected to the support arm 3 can be adjusted by inserting the positioning bolt 32 into one of the positioning holes 111. FIG. 3 shows the cushion 100 at a low position and FIG. 4 shows the cushion 100 at a high position. The position of the backrest 200 can be adjusted by sliding the telescopic post 5 against the sleeve 4 and inserting the fastener 2 into one of the adjusting holes 52. FIG. 3 shows the backrest 200 at a low position and FIG. 4 shows the backrest 200 at a high position. Please refer to FIG. 5, the stopper ring 7 will be blocked by the rails 42 when the telescopic post 5 is being pulled upward for preventing the telescopic post 5 from escaping out of the rails 42.

It will be appreciated by persons skilled in the art that the above embodiment has been described by way of example only and not in any limitative sense, and that various alterations and modifications are possible without departure from the scope of the invention as defined by the appended claims. It will be appreciated by persons skilled in the art that the above embodiment has been described by way of example only and not in any limitative sense, and that various alterations and modifications are possible without departure from the scope of the invention as defined by the appended claims. 

1. An adjustment device for chairs, comprising: a support assembly, having a tube and a fastener penetrating the tube, and the tube being provided with a plurality of positioning holes longitudinally arranged in a row; a support arm, an end of the support arm being connected to the tube and being provided with a positioning bolt penetrating one of the positioning holes, and the other end of the support arm being adapted to connect a cushion; a telescopic post, slidably accommodated in the tube, being provided with a plurality of adjusting holes longitudinally arranged in a row for being selectively penetrated by the fastener; and a backrest support connecting between a backrest and the telescopic post.
 2. The adjustment device of claim 1, wherein the support arm further comprises a connecting ring around the tube and the positioning bolt is disposed at the connecting ring.
 3. The adjustment device of claim 1, wherein a sleeve is accommodated in the tube, an end of the sleeve is formed with a flange hanging on the tube, and an inside of the sleeve is provided with two longitudinally opposite rails.
 4. The adjustment device of claim 3, wherein the telescopic post is formed with two longitudinal troughs for being engaged by the rails, and the adjusting holes are located in one of the troughs.
 5. The adjustment device of claim 3, wherein the sleeve is provided with a through hole penetrating one of the rails for being selectively penetrated by the fastener.
 6. The adjustment device of claim 4, wherein the sleeve is provided with a through hole penetrating one of the rails for being selectively penetrated by the fastener.
 7. The adjustment device of claim 4, further comprising a stopper ring at a lower end of the telescopic post for encompassing the troughs
 51. 8. The adjustment device of claim 1, wherein the backrest support has two opposite ends, the two ends are provided with a first connecting portion for fastening to the telescopic post and a second connecting portion for linking the backrest respectively, and a curved portion is formed between the first connecting portion and the second connecting portion.
 9. The adjustment device of claim 8, further comprising a handle ring on the first connecting portion.
 10. The adjustment device of claim 8, wherein the second connecting portion is a pivot rotatably connecting the backrest. 